TY  - JOUR
AU  - Weiling, Matthias
AU  - Lechtenfeld, Christian
AU  - Pfeiffer, Felix
AU  - Frankenstein, Lars
AU  - Diddens, Diddo
AU  - Wang, Jian-Fen
AU  - Nowak, Sascha
AU  - Baghernejad, Masoud
TI  - Mechanistic Understanding of Additive Reductive Degradation and SEI Formation in High‐Voltage NMC811||SiO x ‐Containing Cells via Operando ATR‐FTIR Spectroscopy
JO  - Advanced energy materials
VL  - 14
IS  - 5
SN  - 1614-6832
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2023-05297
SP  - 2303568
PY  - 2024
AB  - The implementation of silicon (Si)-containing negative electrodes is widely discussed as an approach to increase the specific capacity of lithium-ion batteries. However, challenges caused by severe volume changes and continuous (re-)formation of the solid-electrolyte interphase (SEI) on Si need to be overcome. The volume changes lead to electrolyte consumption and active lithium loss, decaying the cell performance and cycle life. Herein, the additive 2 sulfobenzoic acid anhydride (2 SBA) is utilized as an SEI-forming electrolyte additive for SiOx-containing anodes. The addition of 2 SBA to a state-of-the-art carbonate-based electrolyte in high-voltage NMC811||AG+20% SiOx pouch cells leads to improved electrochemical performance, resulting in a doubled cell cycle life. The origin of the enhanced cell performance is mechanistically investigated by developing an advanced experimental technique based on operando attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. The operando ATR-FTIR spectroscopy results elucidate the degradation mechanism via anhydride ring-opening reactions after electrochemical reduction on the anode surface. Additionally, ion chromatography conductivity detection mass spectrometry, scanning electron microscopy, energy dispersive X-ray analysis, and quantum chemistry calculations are employed to further elucidate the working mechanisms of the additive and its degradation products.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001122818800001
DO  - DOI:10.1002/aenm.202303568
UR  - https://juser.fz-juelich.de/record/1019323
ER  -